// mgo - MongoDB driver for Go
// 
// Copyright (c) 2010-2011 - Gustavo Niemeyer <gustavo@niemeyer.net>
// 
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
// 
//     * Redistributions of source code must retain the above copyright notice,
//       this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above copyright notice,
//       this list of conditions and the following disclaimer in the documentation
//       and/or other materials provided with the distribution.
//     * Neither the name of the copyright holder nor the names of its
//       contributors may be used to endorse or promote products derived from
//       this software without specific prior written permission.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

package mgo

import "fmt"

// ---------------------------------------------------------------------------
// Logging integration.

// Avoid importing the log type information unnecessarily.  There's a small cost
// associated with using an interface rather than the type.  Depending on how
// often the logger is plugged in, it would be worth using the type instead.
type log_Logger interface {
	Output(calldepth int, s string) error
}

var globalLogger log_Logger
var globalDebug bool

// Specify the *log.Logger object where log messages should be sent to.
func SetLogger(logger log_Logger) {
	globalLogger = logger
}

// Enable the delivery of debug messages to the logger.  Only meaningful
// if a logger is also set.
func SetDebug(debug bool) {
	globalDebug = debug
}

func log(v ...interface{}) {
	if globalLogger != nil {
		globalLogger.Output(2, fmt.Sprint(v...))
	}
}

func logln(v ...interface{}) {
	if globalLogger != nil {
		globalLogger.Output(2, fmt.Sprintln(v...))
	}
}

func logf(format string, v ...interface{}) {
	if globalLogger != nil {
		globalLogger.Output(2, fmt.Sprintf(format, v...))
	}
}

func debug(v ...interface{}) {
	if globalDebug && globalLogger != nil {
		globalLogger.Output(2, fmt.Sprint(v...))
	}
}

func debugln(v ...interface{}) {
	if globalDebug && globalLogger != nil {
		globalLogger.Output(2, fmt.Sprintln(v...))
	}
}

func debugf(format string, v ...interface{}) {
	if globalDebug && globalLogger != nil {
		globalLogger.Output(2, fmt.Sprintf(format, v...))
	}
}
